Add unit test for network update

Author: itsmeichigo

WooCommerce/WooCommerceTests/Tools/DefaultConnectivityObserver.swift

@@ -51,6 +51,31 @@ final class DefaultConnectivityObserverTests: XCTestCase {
         // Then
         XCTAssertFalse(observer.isConnectivityAvailable)
     }
+
+    func test_updateListener_returns_correct_status_in_callback_closure() {
+        // Given
+        let network = MockNetwork(status: .satisfied, currentInterface: .wifi)
+        let networkMonitor = MockNetworkMonitor(currentNetwork: network)
+        let networkUpdate = MockNetwork(status: .satisfied, currentInterface: .cellular)
+        let statusExpectation = expectation(description: "Status in callback closure")
+
+        // When
+        let observer = DefaultConnectivityObserver(networkMonitor: networkMonitor)
+        var result: ConnectivityStatus = .unknown
+        observer.updateListener { status in
+            result = status
+            statusExpectation.fulfill()
+        }
+        networkMonitor.fakeNetworkUpdate(network: networkUpdate)
+
+        // Then
+        waitForExpectations(timeout: 0.3, handler: nil)
+        if case .reachable(let type) = result {
+            XCTAssertEqual(type, .cellular)
+        } else {
+            XCTFail("Incorrect result status in callback closure")
+        }
+    }
 }
 
 final class MockNetworkMonitor: NetworkMonitoring {
@@ -65,6 +90,10 @@ final class MockNetworkMonitor: NetworkMonitoring {
         self.currentNetwork = currentNetwork
     }
 
+    func fakeNetworkUpdate(network: NetworkMonitorable) {
+        networkUpdateHandler?(network)
+    }
+
     func start(queue: DispatchQueue) {
         didStartMonitoring = true
     }